A tool machine is composed of hundreds or even thousands of elements. During the assembly process of the elements, assembly error will inevitably occur. Even the elements manufactured in the same batch, their quality may not be the same (due to actual tolerance). Since the performance of each tool machine after assembly may vary, the tool machine must be tested and calibrated before the delivery of the tool machine. However, the testing method which requires the tool machine to have actual motion on a work platform is time consuming and has low efficiency.